This invention relates generally to percussion instrument support mechanisms; and more particularly to an improved, readily and easily installable percussion instrument arm adapter. Percussion instruments such as cymbals and drums are frequently mounted on linkage mechanism in the form of arms that interconnect at multiple points. There is continual need for improved mechanisms which are readily and easily interconnectable by musicians, so as not to loosen or otherwise deteriorate in use, often times involving heavy and frequent impacting of the instruments. So far as I am aware, no prior arm adapter incorporates the unusually advantageous structure, functioning and highly advantageous results as are now incorporated in the herein described arm adapter.